Commenter Cindy points out that Massachusetts bike laws are friendlier to cyclists than ever before, which is of course very comforting. It's even better to see hordes of folks out on the bikes, as they were today: all sorts of folks on all sorts of bicycles. When drivers have lots of reminders that other forms of transportation exist they're more likely to look around a little bit before turning or pulling out; my careful study of human psychology tells me that actual bikes on the road will be more of a factor than a friendly legal climate. We can't even get more than one driver in four to stop for us at the crosswalk when we're on foot and pushing a stroller, and the state's crosswalk laws are hardly new or controversial.
Happily, I don't let it bother me much. When I'm on the street I behave like a vehicle, staying as far to the right as possible but not hesitating to move left before turning or to take the lane when necessary. I find that, with enough time spent out there on the roads, it's not even that terrifying: sure, I expose myself danger from the unaware—like the driver who prompted Cindy's comment—and the insane—like the gentleman who threw a cigarette at me a couple years ago—but most drivers are paying a modicum of attention and will not actually run you over should they happen to see you. In fact, in this case a certain amount of "aggressiveness" is safer than the caution exhibited by riders who aren't used to busy roads and who let themselves get into situations where they have to move across traffic from a virtual standstill.
Just as I don't rely on cycling-specific laws to protect me, I don't always pay the strictest attention to those that aim to regulate my behavior on the roads. As long as there are people saying that bikes don't belong out there with cars, I'm going to interpret traffic regulations liberally to keep myself safe (and moving fast!). I don't need to stop at all stop signs: with much better visibility and maneuverability than the driver of a car I can choose when it's safer to roll through. I can turn right on red even when the sign says otherwise. I can even ride on the sidewalk when that will keep cars from getting stuck behind me. Naturally, I only do any of those when conditions warrant. And hey, I've never caused, or even been involved in, an incident on the roadways! (spills on the ice don't count).
As I continue to ride almost every day, I do so in confidence that my skill and alertness, combined with the skill and alertness of most of the drivers out there, will keep me safe. And while it would be nice if everyone in a car could be aware of the legal rights of cyclists, I'd be content if they're just aware that we're there. Maybe even coming up on the right!